Let's back up this with some proof. If you want a video, I'll try to make one.
I have a Shaymin obtained from the Event at the movie a few months ago, via a WC.
Traded Shaymin over to Platinum, obtained the "Galardia's Flower", Shaymin changes to Sky Forme.
Entered the Wifi lobby, it has been changed so now you can walk around and stuff.
Exited the Wifi lobby without doing anything, no one is connected.
When I checked when I exited, Shaymin is in Land Forme.
I'm 99% sure it will go as the following for any other formes too. I don't think connectivity has anything to do with it. The game justs... resets them as they enter the Wifi/Union Room.
Update: I tried to reuse "Galardia's Flower" it the Union Room, it doesn't allow it. It only allows to set it as a shortcut or cancel, don't ask.
Update 2: Thanks to Syberia, we now know it is limited to local connectivity ONLY. I deleted the other "false" stuff now.
I have a Shaymin obtained from the Event at the movie a few months ago, via a WC.
Traded Shaymin over to Platinum, obtained the "Galardia's Flower", Shaymin changes to Sky Forme.
Entered the Wifi lobby, it has been changed so now you can walk around and stuff.
Exited the Wifi lobby without doing anything, no one is connected.
When I checked when I exited, Shaymin is in Land Forme.
I'm 99% sure it will go as the following for any other formes too. I don't think connectivity has anything to do with it. The game justs... resets them as they enter the Wifi/Union Room.
Update: I tried to reuse "Galardia's Flower" it the Union Room, it doesn't allow it. It only allows to set it as a shortcut or cancel, don't ask.
Update 2: Thanks to Syberia, we now know it is limited to local connectivity ONLY. I deleted the other "false" stuff now.